Liquid detergent dispenser



Sept. 25, 1962 G. R. REITER 3,055,555

LIQUID DETERGENT DISPENSER Filed Nov. 12, 1959 GEORGE R. REITER H ISATTORNEY INVENTOR United States Patent M 3,055,555 LIQUID DETERGENTDISPENSER George R. Reiter, Trumbull, Conn., assignor to GeneralElectric Company, a corporation of New York Filed Nov. 12, 1959, Ser.No. 852,273 4 Claims. (Cl. 222-207) thousands of operations beforefailure should occur.

The principal object of the present invention is to provide a novelliquid dispenser that relies upon the relatively higher resistance toflow in the intake line than in the discharge line so that the designmay accomplish its function Without the use of valves.

A further object of the present invention is to provide a liquiddetergent dispenser for an automatic dishwasher including a valvelesspump that utilizes a flexible diaphragm tor the piston, and has adischarge line that is larger than the intake line so that when the pumpis actuated the discharge line will carry off most of the liquid that isput under pressure.

The preferred embodiment of the present invention incorporates a pumphaving a chamber that is fed by a relatively small intake tube andempties into a relatively large discharge tube. The intake tube has alarge resistance to flow of the liquid while the discharge tube haslittle resistance to the flow. The pump includes a piston in the form ofa flexible diaphragm that is capable of compressing the liquid by meansof an actuator connected to the diaphragm so that most of the liquidwill flow through the discharge line. A liquid storage tank ispositioned at the mouth of the intake tube and liquid flows by gravitythrough the intake tube when the diaphragm is drawn back to enlarge thepump chamber. It is necessary that the outlet end of the discharge tubebe positioned higher than the storage tank so that the liquid will notbe siphoned from the tank.

My invention will be better understood from the following descriptiontaken in connection with the accompanying drawing and its scope will bepointed out in the appended claims.

FIG. 1 is a perspective view of a top segment of the wash tub of anautomatic dishwasher showing on the outer surface of the tub a liquidstorage tank and a liquid dispenser embodying the present invention.

FIG. 2 is a schematic drawing partly in cross section showing the novelpump of the present invention.

Referring in detail to the drawing and in particular to FIG. 1 there isshown a washing compartment or tub 11 which is generally square shapedin plan view. The tub is formed by a series of side walls 12, a topcover and a bottom wall (both of which are not shown). Conventionallythe tub will include two or more dish supporting racks and a rotaryimpeller in the bottom of the tub for paddling the water through thedish racks. Also there will be a water feed pipe for introducing hotwater into the tub during both the rinsing and washing cycles. Also itis necessary to provide a means for introducing the detergent into thetub at the precise moment after the dishes have been preninsed. Firstthere is a liquid storage tank 13 for supplying the detergent to a pump14 which will in turn inject the proper amount of the Patented Sept. 25,1962 liquid into the tub at the precise moment at the beginning of thewashing cycle.

The drawings do not show the method used for supporting the tank andpump trom the outer surface of the tub wall 12, but it should beunderstood that the mounting means forms no part of the presentinvention and that standard methods using bolted or welded brackets orclamps would be used in production to insure a firm support for theseelements. Part of the wall of the tank 13 is broken away to show a port15 that extends through the tub wall 12 so that the tank may be filledwith detergent from within the tub. Of course, the fill opening of thetank would be supplied with a suitable cap (not shown) so that the waterspraying within the tub during the operation of the dishwasher will notdilute the detergent in the tank. The tank will also contain a pressureequalizing bleeder hole in the filler cap or top surface. Accordingly,either the top cover of a portable dishwasher is pivoted open to fillthe tank or the dishwasher tub is pulled out from under the counter toexpose the top opening of the tub.

The pump 14 of the present invention is best shown in detail in FIG. 2.The pump has a chamber 16 for receiving the liquid from an intake line17 which extends down into communication with it and for injecting itinto the tub through a largediameter discharge line 18 which extends upfrom chamber 16 into communication with the tub. The pump housing isformed by a metal cup 19 that is covered over by a cup-shaped rubberdiaphragm 20. For purposes of illustration this pump design is formedwith a metal cup and a rubber cup fastened to each other. However, itshould be readily apparent to those skilled in the art that this pumphousing could also be formed by a metal cylinder that is open at one endwhere the opening is closed by a flat rubber sheet or flexible metalsheet that acts as the piston. This pump 14 could be mounted byfastening clamps or brackets from the tub over the tubes 17 and 18 tohold the pump housing stationary with respect to the tub.

A principal point of novelty in this invention is the relative sizes ofthe intake and discharge lines 17 and 18, that is, the relative size ofthe mini-mum cross-sectional area of the discharge line and of theintake line. The intake line 17 is formed by a small tube with an ID. ofabout V that connects at one end to the tank 13 and at its other end tothe metal cup 19 of the pump housing at 21. The pump 14 is mounted lowerthan the tank 13 as is best seen in FIG. 1 so that the liquid detergentwill flow by gravity into the pump chamber 16. The rubber diaphragm 20is normally urged to its retracted position shown in FIG. 2 to obtainthe maxi mum size chamber within the pump so that the pump will alwaysbe supplied with a sufiicien-t amount of detergent for injecting intothe tub. The diaphragm is operated upon by an actuator or link member 22that is pivotally connected at its top end to embossments 23 formed onthe diaphragm 20, while its opposite end is pivotally connected to aflange of an angle bracket 24 that is fastened to the outer surface ofthe tub wall 12. There is a tension spring 26 that is fixed .at one endto the tub wall and connected at its other end to the actuator 22 tohold the actuator in the retracted position. A solenoid 27 is likewisemounted on the bracket 24 and it has an armature 25 that is connected tothe mid-portion of the actuator 22. Hence, when a control switch 28 ofthe solenoid circuit is closed the armature of the solenoid will shiftto the left forcing the rubber diaphragm to be compressed within themetal cup 19 and putting the liquid detergent under pressure. Because ofthe relatively small diameter of the intake tube 17 and the relativelylarge diameter of the discharge tube 18 with an ID. of about most of theliquid will be forced through the discharge line and out into the tub.Notice in FIG. 1 that the uppermost end of the discharge tube 18 extendsthrough the tub wall 12 at a point higher than the tank 13 to preventthe tubes from siphoning the liquid from the tank. Also, the end of thedischarge tube is provided with a deflector cap 29 having enlargedopenings 30 on the side facing the tub wall '12 that are protected fromthe spray of the dishwasher so that the streams of water playing withinthe tub during the washing cycle will not flow back into the dischargeline and into the pump, resulting in a dilute solution.

Having described above my novel invention of a valveless pump system fordispensing liquids, it will be readily appreciated 'by those skilled inthis art that the Liquid need not be a detergent; the tub need not befor a dishwasher, but it could be used with an automatic clothes washer.A solenoid need not be used as the actuator. It could just as well be aheat motor or a spring biased latch mechanism that is controlled by acam on the automatic cycle timer. In the illustrated embodiment of thisinvention air can be trapped in the pump above the discharge tube 18. Amodification would be to locate the discharge tube at the top of thepump housing or alternatively to turn the pump over on its side so thatthe discharge tube is at the highest point of the pump housmg.

Modifications of this invention will occur to those skilled in this artand it is to be understood, therefore, that this invention is notlimited to the particular embodiments disclosed but that it is intendedto cover all modification-s which are within the true spirit and scopeof this invention as claimed.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A liquid dispenser comprising a pump housing with a chamber thatincludes a fluid-tight reciprocating piston which moves in one directionto enlarge the chamber and moves in an opposite direction for decreasingthe chamber space, a small intake line extending down into communicationwith the pump chamber for feeding liquid by gravity into said chamber,and a discharge line having a minimum cross-sectional area at leastseveral times larger than the intake line leading up from the chamber soas to have a lower resistance to flow than the intake line, whereby whenthe liquid enters the chamber through the intake line and the piston isactuated to compress the liquid, the higher resistance to flow of thesmall intake tube will cause most of the liquid in the chamber to beforced out of the larger discharge tube, thereby functioning as avalveless pump.

2. A washing apparatus comprising a washing tub and a liquid detergentstorage tank mounted on an outer side wall of the tub, a detergentdispenser likewise mounted on the outer side of the tub but positionedlower than the storage tank, the dispenser comprising a pump chamber anda fluid-tight resilient diaphragm that is coupled with an actuator, asmall diameter inlet tube joined at one end to the bottom of the storagetank and at its other end to the pump chamber so that the detergent willfeed by gravity into the chamber, and a discharge tube with a largercross-sectional area than that of the inlet tube leading from thechamber and into the tub at a point higher than the storage tank, thelarge discharge tube having less resistance to flow than the small inlettube so that when the actuator causes the diaphragm to move inwardly ofthe pump chamber to compress the liquid detergent, most of the liquid inthe chamber will flow through the discharge tube and into the tub sothat the dispenser represents a valveless pump.

3. A liquid detergent dispensing system for supplying a measuredquantity of detergent to a washing apparatus, the system comprising adetergent storage tank, a valveless pump for the detergent positionedlower than the tank, and a small intake line feeding the liquid to thepump by gravity, and a discharge line that is at least several timeslarger in cross-sectional area than the intake line with a relativelylow resistance to flow as compared with the resistance to flow of thesmall intake line, the discharge line leading from the pump anddischarging into the Washing apparatus at a point higher than thestorage tank, so that in one condition of the pump the liquid will feedfrom the tank to the pump, and in another condition of the pump theliquid will be under pressure and most of the liquid will pass throughthe discharge line with only a small amount flowing back into the intakeline.

4. A valveless pump for a liquid detergent dispensing system, the pumpcomprising a housing forming a chamber and having an intake line and adischarge line both extending down into communication therewith so thatliquid is fed by gravity from said intake line to said chamber, theintake line having a small bore with relatively ligh resistance to flowWhile the discharge line has a bore with a minimum cross-sectional areasubstantially larger than said intake line so that it has substantiallyless resistance to flow, a fluid-tight rubber-like dia- References Citedin the file of this patent UNITED STATES PATENTS Kinney Oct. 21, 1913Laing Dec. 23, 1958 Seiler Mar. 22, 1960

